Because the parser/compiler can function in a web browser, it can be used with systems that cannot run similar technology on the server. For example, you could build a WordPress plugin with a front-end application that transforms CSS.

It's written in node, so you can install it with npm. All available plugins are installed by default and include some development tools like a watcher and a browser live-reload so it don't need more than few seconds to be ready to start to work.

The parser detects any CSS syntax error found. The output code can be customized to follow your own code style rules (indentation, spaces, string quotes, etc). It has a clean and powerfull API, which make easy to create new plugins.

Since Stylecow is pretty small and hasn't gained a lot of traction in the past 5 or so years since it was first released but also because it serves kind of the same purpose as PostCSS which is much more popular, there have been discussions on merging the two projects together.

PostCSS allows you to opt-in to the features you need with plugins. This allows you to set it up to behave exactly like Sass, with nesting, mixing, extends, and more. On the other hand, it allows you to use plugins by themselves for things like auto-prefixing, minification, and more. You can even s...

Some plugins can only work if initialized after some other plugins. For example, transforming and applying CSS variables needs to run before running a plugin which uses these variables inside conditional transformations.

Not only does Stylus support all the features from Less and Sass, it provides features not found anywhere else: You can get properties from parents and pull them into children and/or mixins - if the property isn't found, it will bubble up until it finds a match Introspective API, where...

One of Stylus' distinguishing features is transparent mixins: reusuable, possibly dynamic styles that look exactly like native CSS properties. This is particularly useful for using future non-prefixed properties and having them transparently expand to their prefixed counterparts without any spe...

Stylus relies heavily on whitespaces to separate and define code blocks. While this makes for a cleaner syntax, it's also easier to make mistakes when indenting stuff, especially when working with someone else's code where you don't use the same style of indentation.

With Garden, you have access to all the core features of a powerful programming language to build your scripts, including functions, variables, namespaces, and data manipulation like map merging or concatenation.

Another big advantage for Sass is the very active community pushing the development forward at a rapid pace. Sass is constantly coming out with bug fixes, and are often the first to come out with improvements. This is an important factor to keep in mind when picking a preprocessor to invest your...

Because Less has a lightweight feature set, is syntactically similar to CSS and can be run client side with file conversion on a page reload, it is easy to pick up by anyone familiar with CSS & the very basics of JS. Also, Less has detailed and well-organized documentation, GUI apps that can...

The '@' symbol is used with Less to declare variables. However '@' already has meaning in CSS, as it is used to declare @media queries and @keyframes. This can result in some confusion when reading the code.

Less does not offer custom functions and instead requires the use of mixins. This is limiting in many ways - Functions cannot be called on shorthand values, they cannot return a value, and code needs to be repeated depending on where the mixin is needed.

The keywords are shortened to 3 letters. For example, "background-color" becomes "bac" and "max-width" becomes "maw". These keywords are far less intuitive than their original form and make the CSS much less readable for those who don't know CSS-On-Diet.